Find missing values with IS NULL.

SQLite: Use IS NULL rather than equality to test for missing data.

CREATE TABLE lesson_items (
    id INTEGER PRIMARY KEY,
    name VARCHAR(40) NOT NULL,
    category VARCHAR(20),
    quantity INTEGER NOT NULL
);
INSERT INTO lesson_items (id, name, category, quantity) VALUES
    (1, 'Tea', 'Drinks', 4),
    (2, 'Coffee', 'Drinks', 8),
    (3, 'Bread', 'Food', 2),
    (4, 'Water', NULL, 0);
SELECT name FROM lesson_items WHERE category IS NULL ORDER BY id;

Expected output EXAMPLE

Water

Details

Requires SQLite 3.40 or later. Run with sqlite3 demo.db in a scratch directory. Result rows below use | between columns, without headers; client display formatting may differ.

Keep in mind

Run each example independently in an empty scratch database or schema; the example includes its own starting table and rows.

✓ Verified

Tested on Ubuntu 24.04.5 LTS · 2026-11-02 18:29:45 UTC · SQLite 3.45.1 · bash 5.2.21-2ubuntu4; coreutils 9.4-3ubuntu6.3

Test inputs, results and environment

The exact published code ran in a dedicated Linux test container with prepared inputs. Snippet process uid 65534 with a read-only root filesystem and temporary working files. Networking disabled. Fixtures and output records are isolated from the application database. Testing covers this example and its stated checks, not every input, operating system, or runtime version. The Linux container shares its host's kernel; this is not a native Windows test.

Architecture / host kernel: x86_64 / 6.18.54.1-microsoft-standard-WSL2
Snippet identity / locale: uid=65534, gid=65534 (unprivileged process) / C.UTF-8
Interpreter invocation: Execute the exact SQL in a fresh database/schema; serialize result rows with | separators
Container image ID: sha256:ec91410a8f6ec3e985830b5e3a0560306d36f8c1c5ccd91a6699abe707123fa3
Code SHA-256: b9289541156d723ef63e8aefefd27d883704be71ccc19d230e038847273fe808
Dependencies: bash 5.2.21-2ubuntu4; coreutils 9.4-3ubuntu6.3

Test input setup

These are the prepared inputs used by the test harness. See Details above for the prerequisites and how to run this example.

# No input files required.

Observed standard output

Water

Exit code: 0. Standard error: empty. Validation: Exact stdout comparison. System-dependent values above are one recorded run.